The sisters, described as loving and adventurous best friends, were found unresponsive lying in the same bed after being helped back to their room the night before

A Minnesota family is trying to understand how two sisters wound up dead while on what was supposed to be a “dream vacation” at a paradise island in the Indian Ocean. Natalie Martinez reports. (Published Thursday, Sept. 29, 2016)

Police in the Republic of Seychelles released the findings Friday morning after the bodies of 37-year-old and Annie Korkki 42-year-old Robin Korkki were found last week inside their villa at the Maia Luxury Resort.

Results showed Robin Korkki, who lived in Chicago’s Wicker Park neighborhood and worked downtown as a trader, died of acute pulmonary edema caused by excess fluid in the lungs. Her sister, Annie Korkki, of Denver, died of the same condition, according to the autopsy, in addition to cerebral edema listed as a contributing cause. Cerebral edema is a swelling of the brain.

On their own the causes of death do not reveal much about how the sisters died, NBC News reports, but a pending toxicology report may be the key to uncovering it.

Seychelles police spokesman Jean Toussaint told NBC News officials hope to learn more from a toxicology report currently being processed at a lab on the island of Mauritius, about 1,000 miles away from the resort where the sisters were found.

The autopsy determined there were "no visible signs of injuries found on the bodies," Toussaint added.

Earlier this week their brother, Chris Korkki, told NBC 5’s affiliate station KARE that their family had been given no information on how his sisters suddenly died on what was supposed to be a “dream vacation.”

"It's all very surreal," said their brother, Chris Korkki, who lives in the suburbs of Minneapolis where the sisters grew up. "We don't know very much. Our family is still very much in shock. We're devastated."

He told The Associated Press he, his mother and brother have traveled to Seychelles for answers and to make arrangements to bring his sisters' bodies back to the U.S.

The sisters and self-described best friends had been traveling for a month and just two days from when they were scheduled to return home when they died.

"They were frequent travelers both domestically and internationally," he said. "They were kind and generous and compassionate, and were wonderful people that had a positive impact on a huge number of people."